usb: dwc2: Extract macro definitions to common header

usb: dwc2: Extract macro definitions to common header

Some macros are shared between host and gadget code, causing duplicated
definitions. Move DWC2 macro definitions from host and gadget code into a
common header to reduce duplication.

Signed-off-by: Kongyang Liu <seashell11234455@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20250110-dwc2-dev-v4-6-987f4fd6f8b2@pigmoral.tech
Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>